Phenolic profile,antioxidant and cytotoxic properties of polar extracts from leaves and flowers of Isatis tinctoria L. (Brassicaceae) growing in Sicily

This study was designed to define and compare the antioxidant and cytotoxic properties of polar extracts obtained from basal leaves (It-BL), cauline leaves (It-CL) and flowers (It-F) of Isatis tinctoria L. growing wild around Acireale (Sicily, Italy). The phenolic profile was characterized by HPLC-PDA-ESI-MS analysis and the correlation between phenolic content and the observed biological effects was established. Further, LC/MS analysis showed that the extracts contain glucosinolates at very low concentrations. The antioxidant activity of the extracts was tested in vitro; It-F was the most effective in the DPPH test (IC₅₀ = 0.437 ± 0.003 mg/mL), whilst It-CL showed the best reducing power (1.546 ± 0.006 ASE/mL) and ferrous ions chelating activity (IC₅₀ = 0.564 ± 0.011 mg/mL). The extracts exhibited anti-proliferative effects against three different human thyroid carcinoma cell lines, and It-BL displayed the strongest activity; particularly, it markedly inhibited the growth of CAL-62 cells, causing nearly 85% reduction of viability at the highest tested dose. No cytotoxicity against Artemia salina was observed. The results of our investigations indicate that the polar extracts obtained from I. tinctoria are a potential source of antioxidant and anticancer compounds, which could be suitable for nutraceutical and therapeutic applications.     

Anti‐HSV‐1 and HSV‐2 Flavonoids and a New Kaempferol Triglycoside from the Medicinal Plant Kalanchoe daigremontiana

Kalanchoe daigremontiana (Crassulaceae) is a medicinal plant native to Madagascar. The aim of this study was to investigate the flavonoid content of an aqueous leaf extract from K. daigremontiana (Kd), and assess its antiherpetic potential. The major flavonoid, kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 1 ), was isolated from the AcOEt fraction (Kd‐AC). The BuOH‐soluble fraction afforded quercetin 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside ( 2 ) and the new kaempferol 3‐O‐β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐rhamnopyranoside‐7‐O‐β‐d ‐glucopyranoside ( 3 ), named daigremontrioside. The crude extract, Kd‐AC fraction, flavonoids 1 and 2 were evaluated using acyclovir‐sensitive strains of HSV‐1 and HSV‐2. Kd‐AC was highly active against HSV‐1 (EC₅₀ = 0.97 μg/ml, SI > 206.1) and HSV‐2 (EC₅₀ = 0.72 μg/ml, SI > 277.7). Flavonoids 1 and 2 showed anti‐HSV‐1 (EC₅₀ = 7.4 μg/ml; SI > 27 and EC₅₀ = 5.8 μg/ml; SI > 8.6, respectively) and anti‐HSV‐2 (EC₅₀ = 9.0 μg/ml; SI > 22.2 and EC₅₀ = 36.2 μg/ml; SI > 5.5, respectively) activities, suggesting the contribution of additional substances to the antiviral activity.     

Chemical Composition,Antibacterial, Schistosomicidal,and Cytotoxic Activities of the Essential Oil of Dysphania ambrosioides (L.) Mosyakin & Clemants (Chenopodiaceae)

We have investigated the chemical composition and the antibacterial activity of the essential oil of Dysphania ambrosioides (L.) Mosyakin & Clemants (Chenopodiaceae) (DA‐EO) against a representative panel of cariogenic bacteria. We have also assessed the in vitro schistosomicidal effects of DA‐EO on Schistosoma mansoni and its cytotoxicity to GM07492‐A cells in vitro. Gas chromatography (GC) and gas chromatography‐mass spectrometry (GC/MS) revealed that the monoterpenes cis‐piperitone oxide (35.2%), p‐cymene (14.5%), isoascaridole (14.1%), and α‐terpinene (11.6%) were identified by as the major constituents of DA‐EO. DA‐EO displayed weak activity against Streptococcus sobrinus and Enterococcus faecalis (minimum inhibitory concentration (MIC) = 1000 μg/ml). On the other hand, DA‐EO at 25 and 12.5 μg/ml presented remarkable schistosomicidal action in vitro and killed 100% of adult worm pairs within 24 and 72 h, respectively. The LC₅₀ values of DA‐EO were 6.50 ± 0.38, 3.66 ± 1.06, and 3.65 ± 0.76 μg/ml at 24, 48, and 72 h, respectively. However, DA‐EO at concentrations higher than 312.5 μg/ml significantly reduced the viability of GM07492‐A cells (IC₅₀ = 207.1 ± 4.4 μg/ml). The selectivity index showed that DA‐EO was 31.8 times more toxic to the adult S. mansoni worms than GM07492‐A cells. Taken together, these results demonstrate the promising schistosomicidal potential of the essential oil of Dysphania ambrosioides.     

2,6‐Dimethoxy‐1,4‐Benzoquinone Enhances Resistance Against the Rice Blast Fungus Magnaporthe oryzae

We investigated the effect of 2,6‐dimethoxy‐1,4‐benzoquinone (DMBQ) on induced resistance to Magnaporthe oryzae in rice. DMBQ concentrations greater than 50 μg/ml inhibited spore germination and appressorium formation in M. oryzae. When rice leaves pretreated with 10 μg/ml DMBQ, which did not show antifungal activity against spore germination and appressorium formation of M. oryzae, were inoculated with M. oryzae spores 5 days after DMBQ pretreatment, blast lesion formation was inhibited compared with control leaves pretreated with distilled water. In addition, infection‐inhibiting activity against M. oryzae was significantly enhanced in rice leaf sheaths pretreated with 10 μg/ml DMBQ. H₂O₂ generation was observed in rice leaves pretreated with DMBQ, and PAL, POX, CHS and PR10a were significantly expressed in these leaves. These results suggested that DMBQ can protect rice from blast disease caused by M. oryzae.     

Comparative assessment of biological activities of different parts of halophytic plant Tamarix articulata (T. articulata) growing in Saudi Arabia

Owing to extremely high salinity and harsh environmental conditions, T. articulata is one of the most abundant wild plants growing in the deserts of Saudi Arabia. Such plants may contain novel compounds to display promising biological activities. Here, in this study, we evaluate the biological activities of methanolic extracts of fresh leaves, dry leaves, stem, and roots of T. articulata. The antioxidant activity was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic and flavonoid content were determined using standard colorimetric methods. Whereas antimicrobial and ant-proliferative activities were determined by standard well-diffusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Our results demonstrate that all methanolic extracts of T. articulata showed antioxidant activity, however, the methanolic extract of dry leaves exhibits promising antioxidant effect with IC₅₀ value 49.08 ± 1.98, which was strongly supported by total phenolic (409.92 ± 6.03 mg GAE/g DW) and flavonoid (177.71 mg QE/g DW) content. Although, antimicrobial activity was also exhibited by all the methanolic extracts, however, methanolic extract of dry leaves exhibits promising antimicrobial activity in Gram-positive bacteria Staphylococcus epidemidis. Furthermore, MTT assay revealed that all methanolic extracts exhibit antiproliferative activity in MCF-7 (breast cancer) and RKO (colorectal cancer) cells with IC₅₀ values ranges from 219 ± 5.112 µg/ml to 253 ± 5.231 µg/ml and 220 ± 4.330 µg/ml to 325 ± 6.213 µg/ml, respectively. However, the most promising antiproliferative effect was displayed by methanolic extract of dry leaves with IC₅₀ values 219 ± 5.112 µg/ml and 220 ± 4.330 µg/ml, respectively. In summary, these findings provide evidence that T. articulata has promising biological activities and can be used for many pharmaceutical activities in the future.     

Exploratory Studies on the in Vitro Anti‐inflammatory Potential of Two Herbal Teas (Annona muricata L. and Jasminum grandiflorum L.), and Relation with Their Phenolic Composition

The need of new anti‐inflammatory drugs has led to the search for safer and more potent molecules in distinct sources, such as natural products. This work aimed to explore the anti‐inflammatory potential of aqueous extracts from two herbal teas (Annona muricata L. and Jasminum grandiflorum L.) in RAW 264.7 macrophages cells and in cell‐free assays. Furthermore, the phenolic composition of both extracts and of their hydrolysates was characterized by HPLC‐DAD, in order to establish possible relationships with the biological activity. In a general way, A. muricata displayed a stronger capacity to inhibit nitric oxide (NO) production and the activity of phospholipase A₂ (PLA₂), displaying an IC₅₀ value of 142 μg/ml against this enzyme. A deeper look at phenolic compounds revealed that aglycones had more capacity to inhibit NO and PLA₂ than their corresponding glycosides, quercetin being clearly the most potent one (IC₅₀ = 7.47 and 1.36 μm , respectively). In addition, 5‐O‐caffeoylquinic acid, at 1.56 μm , could also inhibit PLA₂ (ca. 35%). Our findings suggest that the consumption of both herbal teas may be a preventive approach to inflammatory disorders.     

Chemical Composition,Antioxidant Properties, α‐Glucosidase Inhibitory,and Antimicrobial Activity of Essential Oils from Acacia mollissima and Acacia cyclops Cultivated in Tunisia

The genus Acacia is quite large and can be found in the warm subarid and arid parts, but little is known about its chemistry, especially the volatile parts. The volatile oils from fresh flowers of A. mollissima and A. cyclops (growing in Tunisia) obtained by hydrodistillation were analyzed by GC then GC/MS. Eighteen (94.7% of the total oil composition) and 23 (97.4%) compounds were identified in these oils, respectively. (E,E)‐α‐Farnesene (51.5%) and (E)‐cinnamyl alcohol (10.7%) constituted the major compounds of the flower oil of A. mollissima, while nonadecane (29.6%) and caryophyllene oxide (15.9%) were the main constituents of the essential oil of A. cyclops. Antioxidant activity of the isolated oils was studied by varied assays, i.e., 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2‐azinobis 3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS); the isolated oils showed lowest IC₅₀ (4 – 39 μg/ml) indicating their high antioxidant activity. The α‐glucosidase inhibitor activity was also evaluated and Acacia oils were found to be able to strongly inhibit this enzyme with IC₅₀ values (81 – 89 μg/ml) very close to that of acarbose which was used as positive control. Furthermore, they were tested against five Gram‐positive and Gram‐negative bacteria and one Candida species. Essential oil of A. mollissima was found to be more active than that of A. cyclops, especially against Pseudomonas aeruginosa (MIC = 0.31 mg/ml and MBC = 0.62 mg/ml).     

Reduced Application of Nitrogen Fertilizer Affects the Carbon Metabolism of Leaves and Maintains the Number of Flowers in Coreopsis tinctoria

This study examined the effects of nitrogen (N) fertilizer reduction on the carbon (C) metabolism and yield of Coreopsis tinctoria. A two-year (2020–2021) hydroponic experiment was conducted in accordance with a randomized complete group design with five N levels [0.875 mM Ca(NO₃)₂ (N1), 1.750 mM Ca(NO₃)₂ (N2), 3.500 mM Ca(NO₃)₂ (N3), 7.000 mM Ca(NO₃)₂ (N4), and 14.000 mM Ca(NO₃)₂ (N5)] and three replications. The results showed that low N significantly affected the functional leaf weight, C metabolism, and flower bud (or flower) numbers of C. tinctoria at harvest. Lower-N levels, especially those of the N2 treatment, significantly increased Rubisco, sucrose synthase (SS), sucrose phosphate synthase (SPS), soluble acid invertase (SAI), glucose 6-phosphate dehydrogenase (G6PDH), and 6-phosphogluconate dehydrogenase (6PGDH) activity and maintained the flower number of C. tinctoria. In addition, the balance of carbohydrates (sucrose, starch, glucose, and fructose) and ATP contents was more efficiently maintained under relatively low-N levels. These findings might suggest that reduced application of N fertilizer affects the C metabolism of leaves and maintains the number of flowers in Coreopsis tinctoria. Applying relatively low-N fertilizer levels is also a promising cultivation strategy for C. tinctoria.

     

Comparison of Phytochemical Composition and Biological Activities of Rubus ulmifolius Extracts Originating from Four Regions of Tunisia

In the current study, the phenolic composition, antioxidant and antimicrobial activities of extracts from Rubus ulmifolius Schott leaves harvested in four localities (Sejnen, Tabarka, Faija and Ain drahem) in Tunisia were investigated for the first time. Great differences were found for the chemical composition, total phenol contents and biological activities among the evaluated extracts. HPLC analysis of methanolic extracts showed that the dominant compounds were kaempferol 3‐O‐rutinoside and naringenine. In addition, significant correlations were observed between antioxidant activities and phenolic contents. In fact, leaves collected from Sejnen presented higher total phenol content (53.32 mg GAE/g DW) and antioxidant activities (IC₅₀ = 39.40 mg/l) than the others samples. All extracts showed significant antimicrobial activity against six used bacteria with the inhibition zones diameters and minimal inhibitory concentration values were in the range of 8 – 16 mm and 6.25 – 25 mg/ml, respectively. The highest antimicrobial activities were recorded in Sejnen extract against Gram‐positive bacteria.     

Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress

The effect of different NaCl concentrations (control, 2, 4 and 6 dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α‐pinene, 1,8‐cineole, limonene, linalool, α‐terpineol, and linalyl acetate in which α‐pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS/m) and spring, while 1,8‐cineole varied from 7.42% in high salinity (6 dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β‐carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC₅₀ values obtained in 6 dS/m in spring (375.23 μg/ml) followed by summer (249.41 μg/ml) and fall (618.38 μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.     

Investigations on Antioxidant,Antiproliferative and COX‐2 Inhibitory Potential of Alkaloids from Anthocephalus cadamba (Roxb.) Miq. Leaves

In the present study, an ayurvedic medicinal plant, Anthocephalus cadamba (Roxb .) Miq . commonly known as ‘Kadamb’ was explored for its potential against oxidative stress and cancer. The fractions namely AC‐4 and ACALK (alkaloid rich fraction) were isolated from A. cadamba leaves by employing two different isolation methods and evaluated for their in vitro antioxidant and antiproliferative activity. The structure of the isolated AC‐4 was characterized tentatively as dihydrocadambine by using various spectroscopic techniques such as ESI‐QTOF‐MS, ¹H‐ and ¹³C‐NMR, DEPT, COSY, HMQC, and HMBC. Results of various antioxidant assays viz. 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ABTS cation radical, superoxide anion radical scavenging, and plasmid nicking assay demonstrated that both the fractions viz. AC‐4 and ACALK possess ability to scavenge DPPH, ABTS radicals and effectively protected plasmid pBR322 DNA from damage caused by hydroxyl radicals. Further, when both fractions were evaluated for their potential to suppress growth of HeLa and COLO 205 cells, only ACALK fraction showed antiproliferative effects. ACALK exhibited GI₅₀ of 205.98 and 99.54 μg/ml in HeLa and COLO 205 cell lines, respectively. Results of Hoechst staining in cervical carcinoma (HeLa) cells confirmed that ACALK induced cell death in HeLa cells via apoptotic mode. Both the fractions also inhibited COX‐2 enzyme activity.     

Vibsane‐Type Diterpenoids from Viburnum odoratissimum and Their Cytotoxic and HSP90 Inhibitory Activities

Four new vibsane‐type diterpenoids, vibsanol I ( 1 ), 15‐hydroperoxyvibsanol A ( 2 ), 14‐hydroperoxyvibsanol B ( 3 ), 15‐O‐methylvibsanin U ( 4 ), and a new natural product, 5,6‐dihydrovibsanin B ( 5 ), as well as six known analogues, were isolated from the twigs and leaves of Viburnum odoratissimum. Their structures were elucidated by spectroscopic analyses and chemical derivatization method. All compounds showed different levels of cytotoxicity against five cell lines (HL‐60, A‐549, SMMC‐7721, MCF‐7, and SW480). Remarkably, 14,18‐O‐diacetyl‐15‐O‐methylvibsanin U ( 4a ) showed significant cytotoxicity against HL‐60, A‐549, SMMC‐7721, MCF‐7, and SW480, with IC₅₀ values of 0.15 ± 0.01, 0.69 ± 0.01, 0.41 ± 0.02, 0.75 ± 0.03, and 0.48 ± 0.03 μm , respectively. In addition, vibsanin K ( 10 ) was identified as a HSP90 inhibitor with an IC₅₀ value of 19.16 μm .     

Phytochemical Profile and Biological Activities of Helianthemum canum l. baumg. from Turkey

In the current study, antioxidant, antibacterial activities, and the phenolic compositions of extracts from Helianthemum canum L. Baumg . (Apiaceae) aerial parts were investigated for the first time. The H . canum was extracted with 70% methanol (HCM eOH ) and water (HCW ). Both extracts were determined by total phenolic contents (3 mg/ml), flavonoids (1.5 mg/ml), flavonols (1.5 mg/ml), qualitative–quantitative compositions, iron (II ) chelation activities (0.1 – 5 mg/ml), free radical scavenging activities (DPPH ^?: 0.01 – 0.6 mg/ml and ABTS ^+?: 0.125 – 0.5 mg/ml) and the effect upon inhibition of β ‐carotene/linoleic acid co‐oxidation (1 mg/ml). The peroxidation level was also determined using the thiobarbituric acid method (0.01 – 1.5 mg/ml). The results of the activity tests given as IC ₅₀ values were estimated from non‐linear algorithm and compared with standards. Antibacterial activities of extracts and standards were evaluated against Gram‐ negative and ‐positive ten standard strains using disc diffusion and broth microdilution methods. The MIC results (312.5 – 2500 μg/ml) against tested microorganisms varied from 625 to 2500 μg/ml. In HPLC analysis, 3,5‐dihydroxybenzoic acid was found as the main substance in both extracts. These results showed that HCM eOH was richer in phenolic compounds (284.13 ± 0.30 mg GAE /g extract) from HCW (244.55 ± 0.35 mg GAE /g extract)_. In conclusion, H . canum extracts showed in vitro antibacterial and antioxidant activities.     

Immunoassay‐based Techniques for Early and Specific Detection of Latent Postharvest Anthracnose in Mango

The postharvest anthracnose pathogen Colletotrichum gloeosporioides inciting latent or quiescent infection of mango was detected in early stages using immunoassay methods. Twenty‐five pathotypes isolated from different agroclimatic zones of Tamil Nadu, Karnataka and Pondicherry, India, revealed the variation in protein profile analysis (SDS‐PAGE). The polyclonal antibodies (PCA) were raised against the unfractioned mycelial protein (UMP) and a 40‐kDa polypeptide present in all pathotypes. Standardization of antigen and antiserum dilutions revealed that an antigen dilution of 1 : 200 (protein concentration of 20 μg/ml) and antiserum dilution of 1 : 100 (protein concentration of 40 μg/ml raised against UMP) and 1 : 200 (protein concentration of 20 μg/ml raised against 40 kDa polypeptide) was found to be optimum for the detection of anthracnose pathogen. Both antisera detected the C. gloeosporioides antigen in enzyme‐linked immunosorbent assays (ELISAs), dot immunobinding assays (DIBAs) and Western blots. The specificity in reaction was compared by isolating other Colletotrichum spp. from various hosts viz., C. lindemuthianum (beans), C. falcatum (sugarcane), C. musae (banana), C. capsici (chillies) and Botryodiplodia theobromae (mango). The antisera generated against UMP revealed the cross‐reaction with other host isolates and mango stem end rot pathogen (B. theobromae). The PCA raised against 40‐kDa polypeptide exhibited the specific reaction with C. gloeosporioides isolates in all the immunoassay techniques. By utilizing both PCA, the presence of latent infection was observed in healthy‐looking leaves, flowers and fruits in orchard conditions. The fruit tissues recorded high absorbance values followed by flowers and leaves in all the detection methods. The ELISA technique was also useful in assessing the pathogen inoculum at various biocontrol formulations sprayed mango trees under field conditions. The fluorescent pseudomonad strains mixture (KFP1 + FP7) amended with chitin sprayed at 30‐day intervals revealed the significant reduction in pathogen load than other formulations and unsprayed control.     

Genetically manipulated Brassica genotypes affect demography and performance of Diadegma semiclausum parasitizing Plutella xylostella

The performance of Diadegma semiclausum (Hellen) (Hymenoptera: Ichneumonidae) on Plutella xylostella (L.) (Lepidoptera: Plutellidae) reared on canola's progenitor (Brassica rapa L.), two cultivated canola cultivars (Opera and RGS₀₀₃), one hybrid (Hyula₄₀₁), one gamma‐ray mutant‐RGS₀₀₃ and one transgenic (PF) genotype was compared using the age‐stage, two‐sex life table parameters. All experiments were carried out in a growth chamber at 25 ± 1°C, 65 ± 5% RH and a photoperiod of 16 : 8 (L : D) h. There were significant differences in duration of different life stages of D. semiclausum on its host larvae reared on different plant genotypes. The shortest (12.27 days) and longest (15.21 days) pre‐adult developmental times were observed on cultivar‐RGS₀₀₃ and hybrid‐Hyula₄₀₁, respectively. The intrinsic rate of increase (r) in D. semiclausum ranged between 0.189/day (cultivar‐Opera) and 0.141/day (transgenic‐PF). Moreover, the highest (20.078 offspring) and lowest (12.027 offspring) net reproductive rates (R₀) were observed on cultivar‐Opera and hybrid‐Hyula₄₀₁. The mean generation time (T) of D. semiclausum was the highest (18.34 days) and lowest (15.05 days) on mutant‐RGS₀₀₃ and cultivar‐RGS₀₀₃. The maximum and minimum parasitism values of this parasitoid were observed on canola's progenitor (44.28%) and hybrid‐Hyula₄₀₁ (37.09%). The heaviest pupae (3.82 mg) and females (3.22 mg) of the parasitoid were found on canola's progenitor and cultivar‐Opera, respectively. The results showed that performance of this parasitoid was better on canola's progenitor and cultivated plants known to have higher levels of glucosinolates concentration than others.     

Phenolic Profile of Artemisia alba Turra

The aim of this study was to evaluate flower and leaf methanol extracts of Artemisia alba Turra for their total phenolic and flavonoid contents, antioxidant capacity and to investigate their phenolic composition. The flower extract was richer in total phenolics and flavonoids and possessed higher antioxidant activity through DPPH and ABTS assays. The UHPLC‐PDA‐MS analysis of the flower and leaf methanol extracts revealed similar phenolic profile and allowed identification of 31 phenolic compounds (flavonoids, coumarins, and phenolic acids) by comparison with the respective reference compounds or tentatively characterized by their chromatographic behavior, UV patterns, and MS fragmentations. The presence of hispidulin, jaceosidin, desmethoxycentaureidin, and dicaffeoyl esters of quinic acid in A. alba is reported herein for the first time. The distribution of flavonoids in A. alba from different origins was discussed from chemotaxonomic point of view.     

UHPLC/HR‐ESI‐MS/MS Profiling of Phenolics from Tunisian Lycium arabicum Boiss. Antioxidant and Anti‐lipase Activities’ Evaluation

This study was performed in the aim to evaluate nine different extracts from Tunisian Lycium arabicum for their total phenolic and total flavonoid contents, phytochemical analyses as well as their antioxidant and anti‐lipase activities. The in vitro antioxidant property was investigated using three complementary methods (DPPH, ferric reducing antioxidant power (FRAP), and β‐carotene‐linoleic acid bleaching assays) while anti‐lipase activity was evaluated using 4‐methylumbelliferyl oleate method. From all of the tested extracts the most potent found to be the polar MeOH extracts especially those of stems and leaves. In order to investigate the chemical composition of these extracts and possible correlation of their constituents with the observed activities, an UHPLC/HR‐ESI‐MS/MS analysis was performed. Several compounds belonging to different chemical classes were tentatively identified such as rutin and kampferol rutinoside, the major constituents of the leaves, and N‐caffeoyltyramine, lyciumide A, N‐dihydrocaffeoyltyramine as well as fatty acids: trihydroxyoctadecadienoic acid and hydroxyoctadecadienoic acid isomers were detected abundantly in the stems. These results showed that the MeOH extracts of stems and leaves of L. arabicum can be considered as a potential source of biological active compounds.     

Composition and Biological Activity of Picea pungens and Picea orientalis Seed and Cone Essential Oils

The increasing consumption of natural products lead us to discover and study new plant materials, such as conifer seeds and cones, which could be easily available from the forest industry as a waste material, for their potential uses. The chemical composition of the essential oils of Picea pungens and Picea orientalis was fully characterized by GC and GC/MS methods. Seed and cone oils of both tree species were composed mainly of monoterpene hydrocarbons, among which limonene, α‐ and β‐pinene were the major, but in different proportions in the examined conifer essential oils. The levorotary form of chiral monoterpene molecules was predominant over the dextrorotary form. The composition of oils from P. pungens seeds and cones was similar, while the hydrodistilled oils of P. orientalis seeds and cones differed from each other, mainly by a higher amount of oxygenated derivatives of monoterpenes and by other higher molar mass terpenes in seed oil. The essential oils showed mild antimicrobial action, however P. orientalis cone oil exhibited stronger antimicrobial properties against tested bacterial species than those of P. pungens. Effects of the tested cone essential oils on human skin fibroblasts and microvascular endothelial cells (HMEC‐1) were similar: in a concentration of 0 – 0.075 μl/ml the oils were rather safe for human skin fibroblasts and 0 – 0.005 μl/ml for HMEC‐1 cells. IC₅₀ value of Picea pungens oils was 0.115 μl/ml, while that of Picea orientalis was 0.105 μl/ml. The value of IC₅₀ of both oils were 0.035 μl/ml for HMEC‐1 cells. The strongest effect on cell viability had the oil from Picea orientalis cones, while on DNA synthesis the oil from Picea pungens cones.     

Production and Application of Syringomycin E as an Organic Fungicide Seed Protectant against Pythium Damping‐off

Syringomycin E (SRE) is a cyclic lipodepsinonapeptide with potent antifungal activity and is produced by certain strains of Pseudomonas syringae pv. syringae. In this study, its potential as an organic‐compatible agrofungicide and vegetable seed treatment against the soilborne pathogen Pythium ultimum var. ultimum was examined. A variant of P. syringae pv. syringae strain B301D with enhanced SRE‐producing capabilities was isolated and grown in a bioreactor with SRE yields averaging 50 mg/l in 40 h. SRE was extracted and purified through a large‐scale chromatography system using organic‐compatible processes and reagents. The minimum concentrations of the purified product required to inhibit 50 and 90% of P. ultimum oospore germination were determined as 31.3 and 250 μg/ml, respectively. Drench treatment of cucumber seeds in P. ultimum‐infested potting medium (500 oospores/g) with 50 μg/ml SRE or water with no SRE resulted in 90.2 ± 4.5% and 65.7 ± 4.6% germination rates, respectively. Seed coating with 0.03% (w/w) SRE allowed 65.7 ± 4.6% seedlings to germinate on naturally infested soil while 100.0 ± 0.0% of non‐coated seeds were unable to germinate due to Pythium infection. Organic‐compatible and scalably produced SRE is potentially a novel organic fungicide seed protectant.     

Uptake kinetics and storage capacity of dissolved inorganic phosphorus and corresponding dissolved inorganic nitrate uptake in Saccharina latissima and Laminaria digitata (Phaeophyceae)

Uptake rates of dissolved inorganic phosphorus and dissolved inorganic nitrogen under unsaturated and saturated conditions were studied in young sporophytes of the seaweeds Saccharina latissima and Laminaria digitata (Phaeophyceae) using a “pulse‐and‐chase” assay under fully controlled laboratory conditions. In a subsequent second “pulse‐and‐chase” assay, internal storage capacity (ISC) was calculated based on V_M and the parameter for photosynthetic efficiency F_v/F_m. Sporophytes of S. latissima showed a V_S of 0.80 ± 0.03 μmol · cm^?2 · d^?1 and a V_M of 0.30 ± 0.09 μmol · cm^?2 · d^?1 for dissolved inorganic phosphate (DIP), whereas V_S for DIN was 11.26 ± 0.56 μmol · cm^?2 · d^?1 and V_M was 3.94 ± 0.67 μmol · cm^?2 · d^?1. In L. digitata, uptake kinetics for DIP and DIN were substantially lower: V_S for DIP did not exceed 0.38 ± 0.03 μmol · cm^?2 · d^?1 while V_M for DIP was 0.22 ± 0.01 μmol · cm^?2 · d^?1. V_S for DIN was 3.92 ± 0.08 μmol · cm^?2 · d^?1 and the V_M for DIN was 1.81 ± 0.38 μmol · cm^?2 · d^?1. Accordingly, S. latissima exhibited a larger ISC for DIP (27 μmol · cm^?2) than L. digitata (10 μmol · cm^?2), and was able to maintain high growth rates for a longer period under limiting DIP conditions. Our standardized data add to the physiological understanding of S. latissima and L. digitata, thus helping to identify potential locations for their cultivation. This could further contribute to the development and modification of applications in a bio‐based economy, for example, in evaluating the potential for bioremediation in integrated multitrophic aquacultures that produce biomass simultaneously for use in the food, feed, and energy industries.